This invention relates to lactam amides and lactam dihydroimidazolines and tetrahydropyrimidines also characterized as amido-, dihydro-imidazolinyl-and tetrahydropyrimidylsubstituted tetrahydropyrrolidones or butyrolactams and to their preparation by reaction of a gamma lactam carboxylic acid with a polyamine. The resulting products provide useful dispersants for incorporation in lubricant oil compositions.
The reaction of lactone acetic acid with polyamines to produce the corresponding lactam acid salts and amides useful as lubricant additives is described in U.S. Pat. No. 3,925,232. The lactone acetic acid reactants of the foregoing patent are prepared by hydrolysis of hydrocarbyl, and preferably alkenyl, succinic anhydride.
The reaction of an alkenyl succinic acid or anhydride with an ethylene polyamine to produce a useful dispersant for incorporation in lubricant oil compositions is also well-known and described in U.S. Pat. No. 3,172,892.
Further, it has been proposed in U.S. Pat. No. 3,808,131 to produce lubricant additives by reaction of an alkylene polyamine, monocarboxylic acid or its anhydride and, sequentially, an alkenyl succinic acid or its anhydride, in turn, and a metal salt.
If, however, novel lactam acid amides and particularly lactam acid dihydroimidazolines and tetrahydroyrimidines having significant utility as dispersants in combination with effective corrosion inhibition properties for use in lubricant compositions to be incorporated in fuels, automatic transmission fluids, diesel engines, outboard motors, and the like, could be conveniently and readily prepared, using gamma-lactam carboxylic acids in reaction with a variety of amines, and particularly, polyamines, a significant advance in the state of the art would be effected.